A growing army of PC owners is hoping to use the power of the masses to crack the main security code of Microsoft's Xbox and claim $100,000 in the process.

The bid to break the video game console's encryption has been launched by the Neo project, a group of computing enthusiasts using distributed computing techniques to crack security challenges.

More than 3,500 Neo users were working on the Xbox project as of Monday morning, according to the project's Web site, and had already eliminated 776 million possibilities for the encryption key.

"The Xbox public key is 2,048 bits and nearly impossible to crack with today's methods in a reasonable time," project founder Mike Curry said via e-mail. "So, with that said, we decided to use a random method...that could send a result today, tomorrow or never."

Distributed computing, most commonly known from the Seti@Home project to find signs of extraterrestrial life, divides up major computing tasks among a large number of PCs, which work on the project when they would otherwise be idle.

The Neo Project was initially founded to develop distributed computing software to meet a challenge from RSA Security, which has offered a $10,000 prize for the first person to crack one of the main encryption keys used by the company's PC security software.

Recently, the Neo effort expanded to include a separate project aimed at cracking the encryption key for Microsoft's Xbox console. If successful, the cracking of the Xbox's encryption key could allow hackers to boot an unmodified Xbox with software of their own design. That would satisfy the second part of a $200,000 challenge to run the Linux operating system on the Xbox. Michael Robertson, CEO of Linux company Lindows, was revealed last week as the funder of the contest, known as the Linux Xbox challenge.

The Neo project's Curry said he hasn't been contacted by Microsoft about the contest, and the project's home page indicates the group would offer little resistance if the software giant challenges the effort. "If this Xbox challenge is found illegal and/or (we) are approached by (Microsoft), we will be ditching the Xbox project altogether, as we cannot afford the legal fees," the project's home page states.

Microsoft representatives did not immediately respond to a request for comment.

Microsoft has vigorously defended the Xbox against possible security threats, employing a variety of legal, technical and other measures to defeat "mod chips," gray-market add-ons that allow the consoles to run unauthorized software and copied discs.